The Mexican American War History Essay

The Mexican-American War was a conflict between the United States and Mexico. It commenced on 25 April, 1846 and ended on 2 February, 1848. President Polk played a large role in the United States government’s involvement with the Mexican-American War. Not all American citizens supported the war. There were many individuals who were against to it. Henry David Thoreau, an American writer and philosopher, strongly opposed the war by declaring the United States actions as unethical.

The Mexican-American War was a result of Manifest Destiny. According to Roger Lee of TheHistoryGuy.com, Manifest Destiny was a belief that Americans had a god given right to expand their border all the way to the Pacific Ocean. Not only did Americans believe that they had a right to the land, but they also believed that they had a moral duty to civilize its occupants, which included Native Americans, Mexicans, and Spanish speaking Catholics. According to Encyclopedia Britannica, the Mexican-American War originated from the United States annexation of Texas in 1845 (“Mexican-American War”). Texas had been in a border dispute with Mexico at the time of the annexation; therefore, the conflict transferred to the U.S. Mexico claimed that the border ended at the Nueces River, and the United States claimed it ended at the Rio Grande River.

In 1844, James Polk won the presidential election by campaigning on the idea of expanding the American border to the Pacific Ocean. David A. Clary, author of Eagles and Empires, asserts that Polk’s “territorial ambitions were naked and unashamed and there was never any hesitation on ethical grounds” (64). With no type of military training or experience, Polk kept control over the bigger strategies of the Army and Navy forces before and during the war. He knew that Mexico was in political turmoil, had a limited budget for its military, and had problems getting supplies to its troops. With this information, Polk planned his military strategies accordingly. Mark Crawford, author of Encyclopedia of the Mexican-American War, to “entrust public business to his subordinates” (218). Polk was determined to expand the U.S. borders and nothing would have stopped him from doing so.

One of Polk’s first actions that led to the war was to send Congressman John Slidell to Mexico in 1848. Slidell was to offer Mexico thirty million dollars to buy its Northern Territories, which included present day California, Nevada, Utah, parts of Arizona, New Mexico, Colorado, and Wyoming. According to The U.S. Mexican War, a documentary distributed by PBS, Mexico rejected Slidell and refused to negotiate with the United States. Not happy with the refusal, Polk ordered troops to the Rio Grande knowing it was the disputed territory between the U.S. and Mexico. Once the troops reached the Rio Grande, they built a fortress named Fort Texas. Tensions immediately rose between the two countries. Polk had hoped that Mexico would feel intimidated by the American soldiers’ presence and would agree to sell their Northern Territories to the United States. If intimidation did not work, Polk was counting on Mexican soldiers to fire the first shot. One month after American soldiers arrived at the Rio Grande, Mexican troops attacked a United States patrol party and killed eleven soldiers and captured fifty-two prisoners. Following the attack, Polk demanded that Congress declare war on Mexico. It did so on 13 May, 1846. The Mexican-American War lasted for two years, with the United States winning the war and gaining more than five-hundred thousand square miles of Northern Mexican Territories.

American political views regarding the Mexican-American War were divided. According to Encyclopedia Britannica, Democratic southern states approved the war (Mexican-American War). They had plans on extending slavery to the newly acquired land. The Whig Party viewed Polk’s motives for the war “as conscienceless land grabbing.” Many Whigs were against slavery, and they believed that the purpose of the war was to expand and increase slavery. Abolitionists were very much opposed to the war. Like most of the Whigs, they did not want slavery extended to the new territory. They had no doubt that if slavery was permitted in the newly acquired land, it would enhance the power of the existing southern slave states.

Henry David Thoreau, one of the many abolitionists opposed to the Mexican-American War, publicly shared his views about the war in an 1848 lecture titled “Civil Disobedience.” One year later, the lecture was published. In “Civil Disobedience,” Thoreau argues that an individual should follow their conscience and not support a government that he or she believes is unjust. Referring to the U.S. government’s actions and role in the Mexican-American War, Thoreau writes, “the work of comparatively a few individuals using the standing government as their tool, for in the outset the people would not have consented to this measure” (305). Thoreau believes that the war was instigated by a few aggressive members of the U.S. government, and if it had consulted with the public, the U.S. would not have been involved in the war. It is obvious that Thoreau is referring to President Polk’s determination to acquire Mexico’s Northern Territories at all costs. This includes Polk’s blatant action of placing American troops on the Rio Grande, knowing that it would most likely cause the Mexican government to order its troops to attack the American military. Polk went so far as to hope Mexico would attack first so that it would appear to the rest of the world as the aggressor.

Unfortunately, the aggression of a few top brass in the United States government still exists. In 2003, President George W. Bush pushed for war on Iraq by officially declaring that Iraq had weapons of mass destruction (WOMD). In reality, Bush never had any evidence that Iraq had any WOMD. He was resolved to start a war at all costs, just as Polk was determined to go to war with Mexico. By reviewing President Polk’s determination of acquiring new land for the United States at all costs, and his aggressive conduct of placing American troops on the disputed land between the United States and Mexico, Thoreau is correct by labeling the Mexican-American War as unethical.